One of the best-preserved Roman monuments in the world, and uniquely, one that is still fully inhabited. Diocletian commissioned this enormous fortified palace on the Dalmatian coast in the late 3rd century AD, and it was completed in time for his retirement in 305. After the fall of the Western Roman Empire, refugees from the nearby city of Salona moved inside the walls, converting the mausoleum into a cathedral and the temples into churches. Today some 3,000 people live within the palace precinct.
The palace covers 3 hectares and its walls — up to 28 metres high on the sea-facing side — are still largely intact. The main entrance is through the northern Golden Gate, though most visitors enter through the Bronze Gate on the sea side. The Peristyle, the palace's main ceremonial courtyard, is the natural gathering point and the most atmospheric square in the city. Give yourself at least two hours for a thorough exploration; the warren of lanes and vaulted cellars repays unhurried wandering.